1. Field of the Invention
The present invention relates to a tape cartridge of a compatible type capable of recording and reading out large and small tape cartridges with different widths (thickness measurements from upper face and lower face of the tape cartridges) in common with the same tape driver.
2. Description of the Related Art
It is known to public that large and small tape cartridges with different widths of their body cases can be recorded and read out in common with the same tape drive in this kind of tape cartridge (refer to: JP-A-5-250841 (paragraph 0022, FIG. 1) and JP-A-7-6558 (paragraph 0020, FIG. 1)). According to the tape cartridge disclosed in JP-A-5-250841, in order to absorb a difference of the widths and the measurements of the large and small tape cartridges, a recess portion is formed on a bottom surface of the large tape cartridge and the large and small tape cartridges are mounted in the same tape drive; and in this state, the recess portion is defined as a positioning reference in the large tape cartridge and a bottom surface of the lower case is defined as a positioning reference in the small tape cartridge, and thereby, heights of the tapes of the large and small tape cartridges inside of the tape drive are maintained constant so as to share upper and lower positions of the tape traveling path.
According to the tape cartridge disclosed in JP-A-7-6558, the center of traveling of the tape inside of the tape drive is defined as a reference position, and memory elements to be arranged in the large and small tape cartridges respectively are arranged at the same distance from the reference position. In the memory element, a specification and property of the tape, and the data of setting a device upon filming or the like are recorded.
According to the present invention, an optical path inverted body such as a prism is provided inside of a case of a main body. A detected light that is irradiated from a light emitting element outside of the case of the main body into the case is inversely guided toward a light receiving element outside of the case of the main body by the optical path inverted body so as to detect an end of the tape. A tape cartridge adopting such a classification of optical detection system is known to public in JP-UM-8-7592 (page. 2, a right column lines 29 to 35, FIG. 3).
In order to perform the light detection of the end of the tape, a passage for light injection and a passage for light ejecting are opened at side walls of the case of the main body facing to the optical path inverted body. In many cases, the passage for light injection is opened at an upward part of the side wall of the case, and the passage for light ejecting is formed facing a contact surface of the upper and lower cases. Therefore, when making the large and small tape cartridges with different widths of the cases compatible, in response to the passage for light injection and the passage for light ejecting of the large and small tape cartridges, two dedicated light emitting elements and two dedicated light receiving elements are disposed on the right and left sides of the tape drive respectively, namely, four elements are disposed in total, resulting in making the inner structure of the tape drive complicated and higher cost. It is also possible to dispose the light emitting element and the light receiving element respectively on the right and left sides of the tape drive, and the upper and lower positions of the light emitting element and the light receiving element are switched respectively. In this case, however, a driving mechanism is needed and this makes the structure more complicated.